This UCLA Symposium will address the molecular basis of growth and differentiation factors in embryonic development. The study of mechanisms by which stem cells choose between alternative fates is one of the most intriguing areas in developmental biology. Recent studies in vertebrates have focused on isolation and characterization of grow-factor like molecules and receptors regulating cell proliferation, differentiation and embryonic induction. Considerable progress in this field has led to identification of new vertebrate factors, many of them related to TGF-b, EGF, the interleukins or oncogene products, that are involved in embryonic development. One of the most exciting developments is the realization that there has been remarkable evolutionary conservation from invertebrates through mammals in the structural motifs of proteins affecting cell fate and cellular interactions. This realization has generated a new common ground among developmental biologists with diverse backgrounds and provides new methods for identifying vertebrate genes involved in determining cell fate. This meeting will create an arena in which to measure recent progress in developmental biology, especially of vertebrates, against our knowledge of the biology of growth factors. New growth, differentiation and induction factors and studies of their in vivo developmental functions will be presented, along with recent advances in the genetic analysis of developmental mutants and transgenic animals. A forum for exchanging new ideas and concepts among developmental and cell biologists will be provided. Session Topics Include: Embryonic induction; Transgenic Animals;Hematopoiesis, Angiogenesis and Vasculogenesis; Mesoderm-- Epithelial Interactions; Neural Development; Organ Generation and Differentiation; TGF-b Superfamily; FGF Family; Interleukins and Other Factors Influencing Differentiation.